In some types of wireless networks, a base station (BS) may communicate with mobile stations (MSs) by transmitting radio blocks (herein “transmission signal blocks”) to the mobile stations. Such transmission signal blocks are typically made up of 19, 22, or some other number of bursts. An example of such a network is a network in which network nodes communicate in compliance with a standard such as Global System for Mobile Communications (GSM) standards (phase I originally published 1990, note that GSM standards includes many standards that are continuously evolving) or with Enhanced Data Rates for GSM Evolution (EDGE/EGPRS) standard including release 99 (from march 2000) and later 3G releases (e.g., rel-99, rel-4, rel-5, rel-6, rel-7, and so forth).
When a base station communicates with mobile stations of such networks, the base station prior to transmitting signals containing the transmission signal blocks may perform a number of operations. Such operations may include, for example, reordering, encoding, ciphering, puncturing, and interleaving the transmission signal blocks prior to transmitting the signals that will contain such blocks.
Correspondingly, when the mobile stations receive the transmission signal blocks, several operations may be performed by the mobile stations. These operations include, for example, equalizing, de-interleaving, de-ciphering, de-puncturing, and de-coding the received transmission signal blocks. In addition, other operations may also be additionally performed at the mobile station in order to, for example, support communication between the mobile stations and the base station. For example, in GSM networks, mobile stations are typically required to report back to the base station on a regular basis bit error probability (BEP) data calculated from BEP measurements of the transmission signal blocks received from the base station to be used for link adaptation (i.e., to change the modulation coding scheme). Generally, it might be required that the BEP data to be transmitted back to the base station will be based only on fully transmitted transmission signal blocks. Note that in the general case, the terminology “fully transmitted” is equivalent to “fully received.” From this standpoint, “fully transmitted” terminology will be used throughout the following description to also mean “fully received” unless otherwise indicated.
There are, however, situations where mobile stations may receive transmission signal blocks that were not fully transmitted by the base station. For example, in some circumstances, a base station will go into a discontinuous transmit (DTX) mode in which the base station stops transmitting a transmission signal block sometime during the 19 (or 22) burst period of the transmission signal block (e.g., when someone stops talking and there is no more audio signal to transmit).
Consequently, in order to avoid reporting BEP data that may have been calculated at least in part from the BEP measurement of a transmission signal block that was not fully transmitted by the base station, a mobile station will typically determine the average Signal-To-Interference Noise Ratio (SINR) of a subset of bursts (typically the last two or four bursts) of a transmission signal block to determine whether the transmission signal block was fully transmitted. However, such an approach may not always be an accurate way of determining whether a radio block was fully transmitted. For example, in a synchronized network, if another base station is operating using the same training sequence as the base station of the network, then an average SINR determination of a not fully transmitted radio block may indicate that it was fully transmitted when in fact it was not. This is because SINR only looks at the training sequence of a burst, and since two non neighbor base stations can be using the same training sequence, a false indication of a fully transmitted radio block can result using SINR analysis.